VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.


Go Back   VAF Forums > Model Specific > RV-9/9A
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 01-19-2015, 04:52 PM
WVM WVM is offline
 
Join Date: Jun 2013
Location: Belgium
Posts: 248
Default Still dreaming about the trim, but it can become a nightmare soon...

Hi,

I am currently working on the legendary trim. It appear to be one of the most redone parts in the kit. And that doesn't surprise me at all...

I have put a circular metal bar of 4 mm (about 0.157 inch) in the corner. This was a tip from a fellow builder. But how far can I bend this part without damaging it? I don't really dare to bend over the point that I feel resistance, fearing for a cracking sound... It is also unclear to me how far the trim edge should be from the corner on the "brake". (red arrow). I also hope that the metal bar isn't to big...

Any advise? Thanks!







__________________
RV9 #92188 - Working on wings
Reply With Quote
  #2  
Old 01-19-2015, 05:20 PM
Vlad's Avatar
Vlad Vlad is offline
 
Join Date: Oct 2008
Location: Utah
Posts: 8,446
Default

It's a relatively thick bar I wouldn't use it. The trailing edge of your trim would be larger then your sharp edged elevator. A show plane judge will notice it You can use a leftover wedge instead or nothing at all as per plans. It won't slide out if the blue plastic is still over it.
__________________
Where is N666BK?

Не имей сто рублей, а имей сто друзей.
Reply With Quote
  #3  
Old 01-19-2015, 05:22 PM
Ron RV8's Avatar
Ron RV8 Ron RV8 is offline
 
Join Date: Nov 2010
Location: Okanagan Valley BC, Canada
Posts: 500
Default

I put mine right in the corner of the brake and squeezed a littie at a time until it held the shape I wanted. If you do it in stages and don't squeeze it tight it should not crack...

I don't know about the metal bar though, I would worry it might flex in the middle and result in varying sharpness along the trailing edge. Why not try it both ways on a piece of scrap and see which turns out better?

You want the trim tab to match the elevators, so you should use the same technique for both...
__________________
Ron Townson
Okanagan Valley BC, Canada
RV-8 Completed Dec 2013

Membership renewed Nov 22, 2021
Reply With Quote
  #4  
Old 01-19-2015, 05:28 PM
wirejock's Avatar
wirejock wirejock is offline
 
Join Date: Oct 2005
Location: Estes Park, CO
Posts: 4,778
Default Bending

It's pretty much like any other trailing edge bend. I start with a 1/8" (.125") wood dowel then remove it and finish the bend without one. It really helps to have a target. Make a wedge the shape of the end of the trim tab edge or chord. Get a block of hardwood like oak and cut it diagonally the dimension of the interior of the trailing edge. Remember to cut the correct side of the mark or the kerf will make the inside block too small. The finished product should fit together as a rectangular block when done. You'll need them to bend the ends of the tab anyway. Squeeze till the bend matches the wedge.
To bend the end tabs, get some double sided tape. Put tape on either edge of the interior wedge and insert it into one end lined up with the bend line. Place tape on the mating wedge on top of the trim tab also lined up. Place the sandwich on the end of the bench and clamp it down. Place a block against the end so the two wedges can't slide apart and clamp it to the bench. The top wedge will try to slide downhill. The inside one may also try to slide out. Use a block to keep it from moving too. Now just use a block and hammer to bend the tiny tabs against the wedge. Finish the bend with the mushroom set on the gun with a piece of tape to keep from scratching. Sounds more difficult than it is.
__________________
Larry Larson
Estes Park, CO
wirejock at yahoo dot com
Donated 12/01/2021, plus a little extra.
RV-7A #73391, N511RV reserved (3,000+ hours)
Empennage, wings, fuse, finishing kit done. Working FWF
Disclaimer
I cannot be, nor will I be, held responsible if you try to do the same things I do and it does not work and/or causes you loss, injury, or even death in the process.
Reply With Quote
  #5  
Old 01-19-2015, 07:45 PM
fl-mike's Avatar
fl-mike fl-mike is offline
 
Join Date: Jul 2005
Posts: 1,610
Default

For the trim tab you really don't need the hinged press (or for the rudder and elevators actually). I just put a 1/4" diameter wooden dowel inside and squeezed the tab between a piece of wood and a flat bench top with some c-clamps. You will squeeze it flat (with the TE radius) to get the proper angle with spring-back (and flat skins). Use the trim tab spar to check the bend.




__________________
Mike W
Venice, FL
RV-6A. Mattituck TMX O-360, FP, GRT Sport EFIS, L3 Lynx NGT-9000
N164WM
N184WM reserved (RV-8)....finishing kit in progress. Titan IOX-370
N184P reserved (RV-8QB)
Reply With Quote
  #6  
Old 01-19-2015, 08:15 PM
krw5927 krw5927 is offline
 
Join Date: Aug 2010
Location: Wichita, KS
Posts: 1,987
Default

1) ditch the metal rod.
2) don't worry about a "cracking" sound - you won't hear one and you won't crack the sheet.

Bend a little at a time until it's where you want it. You'll be fine.
__________________
Kurt W.
RV9A
FLYING!!!
Reply With Quote
  #7  
Old 01-20-2015, 12:44 AM
WVM WVM is offline
 
Join Date: Jun 2013
Location: Belgium
Posts: 248
Default

It looks like I need to find a smaller the rod. Maybe ditch it, but still most builders that I know of have had cracks when they didn't use one... I am stunned by the pictures where it is bend flat on the table... I continue to learn... will have another attempt when I am home.
__________________
RV9 #92188 - Working on wings
Reply With Quote
  #8  
Old 01-20-2015, 03:20 PM
WVM WVM is offline
 
Join Date: Jun 2013
Location: Belgium
Posts: 248
Default

Hi,

I think that I'm nearly at the point that I can stop bending, but I notice that especially the middle section of the skin remains more open then the sides. I always used a rod of 3 mm (0.118 inches). The hinged press was nearly completely closed.

In an attempt to get the middle section correct, I tried to bend it by pushing on both sides by hand without the rod.

When I put a ruler on the skin, I notice that it is still ballooning in the middle. But as the press was closed, it is difficult to judge what should be done next to get the ballooning out of the skin.





__________________
RV9 #92188 - Working on wings
Reply With Quote
  #9  
Old 01-20-2015, 03:45 PM
ka6dan ka6dan is offline
 
Join Date: Apr 2008
Location: Dunnellon Fl
Posts: 177
Default

You've gotten to the hard part. Folding the ends can be a problem. Make sure the wedges Yor make / use will make the bend and not result in a bend inbound. Don't ask how I know. Just had to order a new trim pice.
__________________
Ka6dan
RV9A N789KD
Paid My 2022 dues. 😃
Reply With Quote
  #10  
Old 01-20-2015, 04:09 PM
wirejock's Avatar
wirejock wirejock is offline
 
Join Date: Oct 2005
Location: Estes Park, CO
Posts: 4,778
Default Bending

Take the rod out and squeeze it. You want to creep on it till the edges touch the forward spar at rest. Take your time. Squeeze, check, lather, rinse, repeat, drink beer.
__________________
Larry Larson
Estes Park, CO
wirejock at yahoo dot com
Donated 12/01/2021, plus a little extra.
RV-7A #73391, N511RV reserved (3,000+ hours)
Empennage, wings, fuse, finishing kit done. Working FWF
Disclaimer
I cannot be, nor will I be, held responsible if you try to do the same things I do and it does not work and/or causes you loss, injury, or even death in the process.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 05:02 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.